石灰软化法处理地下水源水硬度试验研究

Study on the lime softening process for groundwater hardness treatment

采用石灰软化法处理某地下水源水硬度,结果表明,当石灰投加量为220mg/L,pH为8.7～8.9时,可使原水硬度和碱度分别由300mg/L和250mg/L降至115mg/L和80mg/L以下,去除率分别为61.7%和68%,沉淀和过滤对硬度去除效果影响不大;投加石灰后出水浊度明显升高,投加PAC(聚氯化铝)40mg/L,并与常规工艺联用,可使出水浊度稳定降低至0.15～0.65NTU;试验证明"石灰+PAC+常规工艺"能有效去除水中硬度和浊度,出水煮沸后不再生成沉淀和悬浮物,符合现行《生活饮用水卫生标准》(GB 5749—2006)和用户使用要求,石灰软化法药耗成本估算为0.246元/m3。

The study of lime softening process for groundwater hardness treatment was carried out.The results showed that under the conditions of the lime dosage of 220 mg/L and pH 8.7~8.9,the groundwater hardness and alkalinity could be reduced to 115 mg/L and 80 mg/L,with the removal rate of 61.7% and 68% respectively,and the sedimentation and filter had no great influences on removal effects.The effluent turbidity increased rapidly after lime dosing,and it could be stabilized between 0.15~0.65 NTU using the combination of PAC（40 mg/L） and conventional process.The experiment proved that lime＋PAC＋conventional process could remove the hardness and turbidity in water effectively and no sedimentation and suspending solids would form in boiled water,which met the ＂drinking water sanitary standard（GB 5749—2006）＂ and the users＇ requirements.The cost of lime softening dosage was estimated to be 0.246 Yuan/m3.